Conventionally, finite element mechanical modeling is used for in-situ measurement of mechanical stresses imparted to a silicon die on commercial packaged microelectronic parts or on certification test vehicles. However, such modeling typically involves approximations that do not provide accurate enough determinations of those stresses.
Alternatively, Raman spectroscopy may be used for measuring stress applied to silicon. However to do so requires the use of precision spectroscopy tools and also requires that the silicon to be measured be exposed to the view of the beam, making it impossible to measure silicon encased on a microelectronic package.
For simplicity and clarity of illustration, elements in the drawings have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Where considered appropriate, reference numerals have been repeated among the drawings to indicate corresponding or analogous elements.